This invention relates to a disinfectant cleansing composition.
It is known that infection is spread via skin contact through the transmission of pathogenic microorganisms. Hitherto, in order to reduce the presence of such organisms it has been known to scrub the skin with a solution containing a surfactant followed by application of an antiseptic.
In recent years it has been suggested that it would be desirable to combine the washing and disinfectant actions in a single operation by providing a composition comprising both an antimicrobial agent and a surfactant. It has been found however that many antimicrobial agents such as chlorhexidine [N,Nxe2x80x2-bis(4-chlorophenyl)-3,12-diimino 2,4,11,13-tetraazatetradecanediimidamide]digluconate and other chlorhexidine salts are incompatible with anionic surfactants, and are reduced in their antimicrobial activity by nonionic surfactants, thus requiring addition of more antimicrobial agent in order to retain sufficient biocidal activity at the amount of surfactant required for satisfactory foam formation.
In particular, U.S. Pat. No. 3,855,140 assigned to Imperial Chemical Industries describes a skin cleansing composition comprising a soluble salt of chlorhexidine in combination with a polyoxyethylenepolyoxypropylene block copolymer. In order to obtain sufficient sudsing of the polymer it is necessary to use high proportions of the surfactant in amounts of the order of 20-25%. High amounts of chlorhexidine are consequently required to maintain the desired antimicrobial activity. Such high amounts are undesirable as it is known that surfactants may affect the skin adversely by defatting, and causing in combination with biocides such as chlorhexidine, irritation to the skin. Further the ingredients of the composition can be costly.
It would be desirable therefore to provide a composition in which the amount of antimicrobial agent and surfactant is reduced whilst maintaining sufficient antimicrobial activity and sudsing ability.
In this regard, in order to provide such a composition, WO 95/09605 teaches one to combine a phenolic disinfectant with an alkylpolyglucoside surfactant. As indicated in that patent however, such compositions although showing good biocidal activity against most microorganisms, are incapable of disinfecting surfaces contaminated by the microorganism Pseudomonas aeruginosa to which the compositions are inactive.
It is an object of the invention to substantially ameliorate the disadvantages of the prior art.
According to a first aspect of the invention, there is provided an antiseptic cleansing composition comprising an antimicrobial agent, an effective amount of an alkylpolysaccharide surfactant, at least one alkyl alcohol and at least one aryl alcohol.
According to a second aspect of the invention there is provided a method of decontaminating surfaces contaminated with bacteria including the Pseudomonas microorganism, which method comprises contacting the surface with the disinfectant cleansing composition of the first aspect.
Typically the cleansing composition comprises an inert carrier, and optionally other additives.
The alkylpolysaccharide surfactants are also known in the art as alkylpolyglucosides, however, for the purposes of the following discussion, the surfactant will be termed an alkylpolysaccharide.
Preferably, the content of the surfactant present in the composition does not exceed 6% w/v.
Preferably the alkylpolysaccharide is an alkylpolysaccharide of the formula: 
wherein n is an integer between 5 and 19, and
m is an integer between 1 and 3.
In the above formula the surfactant alkyl polysaccharide shown contains glucose units, however the invention is not limited thereto and other sugar units can be substituted for one or more of the glucose units. Other sugar units which might be included in the alkylpolysaccharide include maltose, arabinose, xylose, mannose, galactose, gulose, idose, talose, allose, altrose, sucrose, fructose, sorbose, levulose, lactose, allulose, tagatose, alloheptulose, sedoheptulose, glucoheptulose, mannoheptulose, guloheptulose, idoheptulose, galactoheptulose, taloheptulose and derivatives thereof.
Suitable antimicrobial agents include chlorhexidine and its salts; dichlorophene, other chlorophenol derivatives such as p-chloro-m-xylenol, chlorophene and o-phenylphenol, 2,4,4-trichloro-2-hydroxy-diphenylether (triclosan); octenidindihydrochloride (CH3xe2x80x94(CH2)7xe2x80x94NHONxe2x80x94(CH2)10xe2x80x94NOxe2x80x94NH(CH2)7xe2x80x94CH2 or any other salt thereof and quaternary ammonium compounds.
Suitable salts of chlorhexidine include the gluconate, isethionate, formate, acetate, glutamate, succinamate, monodiglycolate, dimethanesulfonate, lactate, diisobutyrate or the glucoheptonate salts.
Preferably the antimicrobial agent has a water solubility of at least 0.001% w/v at ambient temperature.
When the antimicrobial agent is chlorhexidine digluconate it is used in an amount preferably not exceeding 4.5% w/v. When the antimicrobial agent is 2,4,4-trichloro-2-hydroxydiphenylether (triclosan) it is used in an amount preferably not exceeding 3% w/v.
The alkyl alcohol is preferably a lower alkyl alcohol (herein defined as an alcohol having less than 6 carbon atoms) such as ethanol, iso or n-propanol, most preferably the alkyl alcohol is isopropanol or n-propanol. The alcohol content preferably does not exceed 70% w/v. When the composition is in an aqueous carrier (for example for use in hand washing) the alcohol is desirably iso or n-propanol or a combination thereof and is preferably present in an amount of from 3 to 10% w/v, most preferably 4 to 8% w/v. When the composition is an alcoholic solution (for example for a rapid cleaning self-drying solution) the alkyl alcohol will be preferably be 55-75% w/v.
The aryl alcohol is preferably a benzylalcohol, phenylethylalcohol, phenoxyethanol, phenoxypropanol or a chlorinated derivative thereof. For application to skin, phenoxyethanol and phenoxypropanol are preferred. Preferably the aryl alcohol is present in an amount not exceeding 3% w/v.
An inert carrier can be usedxe2x80x94for example water or a lower alcohol such as ethanol.
The composition may further comprise one or more of the following integers:
(a) a solubilising agent for example propylene glycol, a hydrotrope or mixtures thereof. Suitable hydrotropes include urea, cumene sulphonate, toluene sulfonate, xylenesulphonate and the ethanolamine salts of citric and other hydroxycarboxylic acids.
(b) a foaming agent such as an alkylaminooxide, alkylmono or diethanolamides. Examples of foaming agents are lauryl or cocodiethanolamide or monoethanolamide condensates or the lauryl or cetyl dimethylamineoxides.
(c) viscosity modifiers such as cellulose derivatives, guar resins and carbopol resins.
(d) preservatives such as imidazolidinyl, urea derivatives (Germabenes), methyl or propyl parabens (p-hydroxy benzoic esters).
(e) other conventional additives such as colouring agents, fragrances, antioxidants, emolients, moisturisers, stabilising agents and thickeners such as carboxymethylcellulose.
(f) optionally, additional surfactants including amphoteric surfactants, anionic surfactants and nonionic surfactants. Suitable additional surfactants include quaternary ammonium compounds or a small amount of a high foaming anionic surfactant such as laurylethoxysulfonate, sarcosinates, sodium laurylethersulphate. The additional ingredients are selected to avoid possible incompatibility with any of the other ingredients of the composition and especially with regard to the antimicrobial agents.
The pH of the composition is typically adjusted to pH 5 to 7, most preferably 5.5 but is not limited to this pH. When chlorhexidine is used as the antimicrobial agent, a pH greater than 8 should be avoided to prevent precipitation of the chlorhexidine free base. Most organic acids compatible with the composition, such as lactic, acetic, citric and gluconic acids, preferably gluconic acid, can be used to adjust the pH.
The term xe2x80x9ccomprisingxe2x80x9d as herein used is used in an inclusive sense, that is to say in the sense of xe2x80x9cincludingxe2x80x9d or xe2x80x9ccontainingxe2x80x9d. The term is not intended in an exclusive sense (xe2x80x9cconsisting ofxe2x80x9d or xe2x80x9ccomposed ofxe2x80x9d).